Nems control device having a digital delay module

Abstract

The present application relates to a device for controlling a micro-electromechanical system MEMS or a nano-electromechanical system NEMS comprising a feedback loop provided with: means ( 130 ) for digitizing at least one analog signal from said MEMS or said NEMS and for delivering a given digital signal, a programmable delay module ( 170 ) for inducing a given delay selected from a plurality of predetermined delays to said given digital signal and delivering one or more delayed digital signals according to said given delay to excitation means of the MEMS or NEMS.

1 . A device for controlling a micro-electromechanical system MEMS or a nano-electromechanical system NEMS comprising a feedback loop provided with:
 means ( 130 ) for digitizing at least one analog signal from said MEMS or said NEMS and for delivering a digital signal,   a programmable delay module ( 170 ) for inducing a delay selected from a plurality of predetermined delays to said digital signal and delivering one or more delayed digital signals to excitation means of the MEMS or NEMS.   
     
     
         2 . The device for controlling a micro-electromechanical MEMS or NEMS according to  claim 1 , wherein among said delayed digital signals are a first signal (S D1 ) and a second signal (S D2 ) having a frequency equal to the resonance frequency of the MEMS or NEMS, the first signal and the second signal being in opposite phases. 
     
     
         3 . The device for controlling a micro-electromechanical MEMS or NEMS according to  claim 1 , wherein from said delayed digital signals (S D1 , S D2 ) are a first and a second frequency signals having a frequency equal to half the resonance frequency of the MEMS or NEMS, the first and the second signal being in phase quadrature. 
     
     
         4 . The controlling device according to  claim 1 , wherein the programmable delay module ( 170 ) comprises:
 means ( 177 ) for delivering a plurality of signals (OUT 1 , . . . , OUT 64 ) phase-shifted with respect to an input signal (Sc) of said delay unit, said signals being phase-shifted respectively by a plurality of predetermined phase shifts,   selecting means ( 179 -SLR 1 , . . . , SLR 6 ) for selecting at least one phase-shifted signal from said plurality of phase-shifted signals,   frequency selecting means ( 179 -SLF) between a frequency equal to the frequency of said input signal and a frequency equal to half the frequency of said input signal,   the signal(s) output from said programmable delay module ( 170 ) having a phase shift equal to the phase shift of said phase-shifted signal and a frequency equal to the frequency or half the frequency of said input signal.   
     
     
         5 . The controlling device according to  claim 4 , wherein the programmable delay module ( 170 ) comprises means ( 172 ,  174 ) forming a phase locked loop,
 the means ( 177 ) for delivering a plurality of phase-shifted signals comprising a voltage-controlled delay line having a first input receiving said first digital signal and delivering a feedback signal (Sdly), the control voltage of the delay line depending on a difference between said digital signal and said feedback signal (Sdly).   
     
     
         6 . The controlling device according to  claim 1 , further comprising means ( 150 ) for measuring the frequency of said digital signal (Sc). 
     
     
         7 . The controlling device according to  claim 1 , further comprising a configuration selecting module ( 210 ) provided with a first input (CS) connected to the digitizing means ( 130 ) and a second input (ET), the configuration selecting module ( 210 ) being also provided with a first output (T) and a second output (CE) connected to the programmable delay module ( 170 ), the configuration selecting module being adapted to assume:
 a first configuration in which the first input (CS) is connected to the second output (CE), the second input (ET) being connected to the first output (ST),   a second configuration in which the first input (CS) is connected to the first output (ST), the second input (ET) being connected to the second output (CE).   
     
     
         8 . The controlling device according to  claim 7 , wherein the configuration selecting module is provided such that:
     Tp   (ET/ST)-config1   =Tp   (CS/ST)-config2   +Tp   (ET/CE)-config2 ,     10* Tp   (CE/CS)-config1   <Tp   (CS/ST)-config2 , and     10* Tp   (CE/CS)-config1   <Tp   (ET/CE)-config2 ,   
       with Tp (ST/ET)-config1 , the propagation time of a signal in said first configuration between said second input (ET) and said first output (ST), Tp (CS/ST)-config2 , the propagation time of a signal in said second configuration between the first input (CS) and the first output (ST), and Tp (ET/CE)-config2 , the propagation time of a signal in said second configuration between the second input (ET) and the second output (CE), Tp (CS/CE)-config1  the propagation time of a signal in said first configuration between the first input (CS) and the second output (CE). 
     
     
         9 . The controlling device according to  claim 8 , comprising:
 means for, when the configuration selecting module is in the first configuration, determining Tp (ET/ST)-config1 ,   means for, when the switch configuration module is in the second configuration: determining a Tesbo delay between a test signal, injected into the second input (ET) and which frequency is equal to the resonance frequency of the MEMS or NEMS and a signal in response to this test signal extracted from said first output (ST),   said given delay being selected such that: n/(Fr)−(Tp (ET/ST)-config1 −T esbo ), with n an integer and Fr the resonance frequency of the MEMS or NEMS.   
     
     
         10 . The controlling device according to  claim 1 , further comprising: an output interface ( 190 ) having charge and/or voltage level adapter means at the output of the programmable delay module ( 170 ). 
     
     
         11 . A microelectronic device comprising at least one MEMS or NEMS and a controlling device according to  claim 1 .